In a large, heavy saucepan bring the water to a boil. Add a generous teaspoon of salt and the grits and stir with a wooden spoon to combine. When grits thicken add milk, cream and butter and return to a boil. Reduce heat to a simmer, cover sauce pan and cook for 45 minutes to one hour, until grits are tender, smooth and creamy. Taste and season with salt and pepper.